FOSSORIAL WASPS. 125 



FAMILY XVI. Larrldce. 



Mandibles usually deeply emarginate on the outside near the 

 base ; four front tibiae with a single spine at the tip ; . hind tibii 

 with two spines. 



The species of this family are generally rather small insects, 

 few of the species measuring half an inch in length. They are 

 usually black, sometimes with the abdomen red at the base ; or 

 the face is adorned with silvery pubescence. 



FAMILY XVII. Nyssonidce. 



"Mandibles not emarginate beneath; legs subspinose." 

 (Smith.) 



This family much resembles the last. Smith, in his Catalogue 

 of British Fossorial Lepidoptera, gives an account of the habits of 

 Mellinus Arvensis, Linn., a black species about half an inch long, 

 with yellow stripes on the abdomen, and yellow legs. It pro- 

 visions its nest with flies, and, not being able to capture them by 

 swiftness, runs past them when they are resting, in an unconcerned 

 manner, till they are thrown off their guard, when they are pounced 

 upon, and carried off to the nest. 



FAMILY XVIII. Crabronidce. 



Head large and square ; antennae often thickened at the tips ; 

 abdomen oval or elliptic, and sometimes clavate or petiolated; 

 mandibles with the outer margin but slightly curved ; prothorax 

 very short. 



A very extensive group, as used by Smith. Edward Saunders, 

 however, in his " Synopsis of British Heterogyna and Fossorial 

 Hymenoptera " (Transactions of the Entomological Society of Lon- 

 don for 1880), admits three families, viz. Pemphredonidce, Mimesidce, 

 and Crabronidce. The species are black, with yellow spots and 

 bands, and often with silvery pubescence on the face ; they may 

 often be seen resting on flowers. The small species of Crabro 

 form their burrows in the pith of bramble, rose, etc., or in rotten 

 wood ; others burrow in the ground. The genera Mimesa, 

 Shuck., and Psen, Latr., are black, with red legs, or with the 

 petiolated abdomen red at the base. Some of the smaller species 

 store up gnats or aphides. 



